1. Field of the Invention
This invention relates to a device for loading or unloading a magnetic disc pack, and particularly to a device for loading or unloading a magnetic disc pack used for a magnetical recorder or a reproducer for an electronic camera and the like and capable of magnetically recording still image information and the like.
2. Description of the Prior Art
Recently, there has been developed an electronic still camera system wherein an image pickup device such as a charge coupled device (CCD) or an image pickup tube is combined with a recording device using a magnetic disc which is an inexpensive recording medium and has a comparatively high memory capacity. With this system, a subject is still-photographed electronically and the image is recorded into a rotating magnetic disc, and the reproduction of an image is carried out by a television, a printer or the like. Such systems have become the object of public attention.
The magnetic disc utilized in the above-described system is generally used in the form of a magnetic disc pack. This magnetic disc pack has rotatably mounted therein a magnetic disc capable of magnetically recording therein still image information and the like, and is installed on a magnetic recorder assembled into an electronic camera, or on a reproducer integrally formed on the magnetic recorder or separately formed therefrom. In installing the magnetic disc pack in the magnetic recorder or the reproducer in the electronic camera, it is troublesome and inconvenient to directly couple a center hole formed in a center core located at the central portion of the magnetic disc in the magnetic disc pack onto a rotary drive shaft of the magnetic recorder or reproducer. It is possible that the magnetic disc pack cannot be accurately installed onto the magnetic recorder or reproducer. In order to eliminate the above-described difficulty, there has been proposed a device for loading or unloading a magnetic disc pack, the device including a lid supported on a main body of the magnetic recorder or reproducer and an inner bucket supported by the main body or the lid and having received therein the magnetic disc pack. The magnetic disc pack is inserted into the inner bucket and then the lid is closed, whereby the magnetic disc in the magnetic disc pack inserted into the inner bucket is coupled onto a rotary drive shaft of the main body of the magnetic recorder or reproducer.
Now, it is necessary to accurately couple the center core of the magnetic disc onto the rotary drive shaft. If this coupling is unsatisfactorily made, there is a possibility that the magnetic head cannot accurately record the image signals on the magnetic disc or reproduce the same therefrom. For this reason, there has heretofore been proposed a magnetic chuck type device, in which the rotary drive shaft is coupled into the center hole of the center core of the magnetic disc, while, at the same time, the center core is attracted toward the drive shaft by a magnetic force of a magnet secured to the rotary drive shaft. Even this arrangement is unsatisfactory.
Furthermore, during unloading of the magnetic disc pack, the supply of electric current to the rotary driving source is turned off. However, the drive shaft still rotates due to the inertial force. In consequence, under this condition, if the lid is opened and the center core of the magnetic disc is withdrawn from the driving source, then there is a possibility of damaging the center core and/or the drive shaft.